Small-Scale Modeling of Metal-Plate-Connected Wood Truss Joints

The objective of this research was to develop 1/3-scale models of full-size (prototype) metal-plate-connected wood truss joints and a complete truss using similitude theory. To verify material properties, we compared moduli of elasticity of prototype and 1/3-scale model boards. Although the variation in stiffness of the model was greater than that of the prototype, the average properties of the model and prototype were similar. The resulting average design stiffness of 1/3-scale tension splice joints was within 1 % of the prototype joint stiffness, while the ultimate load was 7 % lower than the prototype. Stiffness and strength of model heel joints were within 22 % and 17 %, respectively, of the stiffness and strength of their prototypes. Finally, ten complete model trusses were fabricated and tested; their average stiffness and strength were 780 N/mm and 17.3 kN, respectively, after scaling up by similitude. Modeling full-size truss connection behavior up to the design load, and possibly to failure, with small-scale models and similitude theory may be feasible.